This study was designed to measure the effect of free glutamine or glutamic acid supplementation on small intestinal growth and disaccharidase enzyme activity in 7-day-old miniature piglets. The piglets received one of three total parenteral nutrition solutions exclusively for 7 days. All three solutions were isonitrogenous and isocaloric, and glutamine or glutamic acid was included at physiological levels (5% of the total amino acid content) in two of the three solutions; the third (control) contained neither glutamine nor glutamic acid. No differences were seen between groups in plasma glutamine or glutamic acid concentrations. Similarly, no effect was observed on small intestinal protein or DNA content or on the specific activities of lactase, sucrase, or maltase. These data demonstrate that in the healthy miniature piglet, parenteral glutamine or glutamic acid supplemented at physiological doses does not influence small intestinal growth and development.